1. Field of the Invention
The present invention generally relates to image processing and, more particularly, to an image processing apparatus and an image processing method in which image data generated by subjecting page description language (PDL) data to raster image processing (RIP) is printed on a recording paper, and a storage medium.
2. Description of the Related Art
An image forming apparatus rasterizes data described by page description language (hereinafter referred to as PDL) into a bitmap image (raster image) and prints based on the raster image and prints based on the raster image. A process for rasterizing the PDL data into the raster image is referred to as rasterization or raster image processing, abbreviated to RIP.
In a case where the image forming apparatus subjects the PDL data to the RIP process to print, while the image forming apparatus is printing on page “m,” the image forming apparatus performs the RIP process of page “m+1” in parallel. As described above, the method of performing the RIP process in parallel with printing is referred to as “RIP While Print.” The image forming apparatus uses the RIP While Print to allow reducing time necessary for printing after receiving the PDL data.
On the other hand, if a condition is different in fixing pigment to recording paper to form an image thereon, a problem occurs that a predetermined color is not represented on the recording paper. For example, in an electrophotographic image forming apparatus, a change in temperature of a fixing heater in fixing a toner to the recording paper changes a tint on the recording paper.
For that reason, if a high image quality is needed for a print result, a recording paper is caused to pass through the fixing heater during printing at regular intervals, the temperature of the fixing heater is controlled while the recording paper is passing, and the temperature of the fixing heater needs to be kept constant in fixing the toner to the recording paper.
If it takes a lot of time to perform the RIP process on a page, the following page cannot be printed at an assumed interval, which changes the temperature of the fixing heater. This causes time (cycle down time) during which printing cannot be performed until the temperature of the fixing heater is restored again to the previous temperature.
To solve this problem, an image forming apparatus being high in image quality has adopted a method in which the PDL data on all pages are subjected to the RIP process before printing is performed uniformly instead of performing the RIP process in parallel with printing, and thereafter printing is performed. The above method of performing printing after the RIP is referred to as “RIP Then Print.” Since the method of “RIP Then Print”, however, does not perform printing until the rasterization of all pages is ended, the method of “RIP Then Print” can take longer time to output a print result than that of “RIP While Print.”
The following technique is known as the one for reducing time consuming until a print result is output. Japanese Patent Application Laid-Open No. 2009-116752 discusses a technique in which information about the PDL is received in advance and a corresponding interpreter is developed to a memory, thereby reducing time for developing the interpreter corresponding to the PDL to be sent to the memory.
Japanese Patent Application Laid-Open No. 2007-108924 discusses a technique in which, if an image transmission source is low in processing capacity of terminal information, the RIP process is started after the transmission of data and, if the image transmission source is high in the processing capacity, the RIP process is started while data are being transmitted.
In the techniques of the above patent documents, the time consumed until the printing is ended is reduced by advancing the timing at which the RIP process is started, and both techniques use the method of “RIP Then Print.” For that reason, the printing in the method of “RIP Then Print” is never performed until rasterization on all pages is ended to take a longer time than the printing in the method of “RIP While Print.” In the conventional techniques, either of “RIP While Print” or “RIP Then Print” is selected, so that there is a problem in which it takes much time to output print result depending on setting of print job or print environment.